Mice immunized with HSV529 produce HSV-2-specific IgG1 and IgG2a antibodies, neutralizing antibodies, and HSV-2-specific splenic lymphocytes secreting IFNγ and IL-5.

<p>BALB/c mice (n = 10/group) were immunized with HSV529 (10⁴ CCID₅₀, 10⁵ CCID₅₀, or 10⁶ CCID₅₀) or PBS by the i.m. route on days 0 and 21. Sera were collected on days 21 (D21; n = 10) and 41 (D41; n = 5). (A) HSV-2-specific IgG1 and IgG2a antibody titers in the sera were determined by ELISA using a lysate prepared from HSV-2-infected Vero cells and secondary antibodies specific for mouse IgG1 and IgG2a. (B) HSV-2 neutralizing antibodies in the sera were measured by preincubating dilutions of heat-inactivated sera with 100 CCID₅₀ of live HSV-2 (strain G) virus for 1 hour prior to infection of Vero cell cultures. Infected cells were detected with anti-HSV glycoprotein D antibodies. The serum dilution that neutralized 50% of the virus (SN₅₀) was determined by plotting the neutralization activity versus the serum dilutions. Splenic lymphocytes secreting IFNγ (C) or IL-5 (D) in response to <i>ex vivo</i> stimulation with heat-inactivated HSV-2 (strain G) were counted using an ELISPOT assay. Error bars represent standard error of the mean.